The disclosed aspects relate generally to communications between and/or within devices and specifically to methods and systems for providing an improved collision resolution mechanism for handling multiple near field communication (NFC) device that support at least a NFC type-A radio frequency (RF) technology (e.g., NFC-A devices) where one or more of the NFC-A devices may not support single device detection (SDD).
Advances in technology have resulted in smaller and more powerful personal computing devices. For example, there currently exist a variety of portable personal computing devices, including wireless computing devices, such as portable wireless telephones, personal digital assistants (PDAs) and paging devices that are each small, lightweight, and can be easily carried by users. More specifically, the portable wireless telephones, for example, further include cellular telephones that communicate voice and data packets over wireless networks. Many such cellular telephones are manufactured with ever increasing computing capabilities, and as such, are becoming tantamount to small personal computers and hand-held PDAs. Further, such devices are enabling communications using a variety of frequencies and applicable coverage areas, such as cellular communications, wireless local area network (WLAN) communications, NFC, etc.
The NFC Forum Activity specification defines a collision resolution procedure to use when resolving multiple devices, tags, and cards that use various NFC radio frequency (RF) technologies, such as but not limited to NFC-A, NFC-B, NFC-F, etc. As applied with respect to NFC-A, the process includes performance of a logical loop that is executed multiple times to differentiate each device in an operating volume (e.g., collision resolution). Further, as defined in version 1.0 of the NFC Forum Activity specification, a determination of whether NFC-A single device detection (SDD) is supported by any of the devices in the operating volume is made once at the beginning of the collision resolution logical loop (e.g., before the logical loop performs SDD). The collision resolution logical loop allows a polling device to receive a sensing response (SENS_RES) message as part of each iteration of the loop where each newly received sensing response message may indicate fewer collisions. Once the collision resolution logical loop has been entered, the polling device is continually prompted to send NFC-A SDD commands, even when, during the execution of the collision resolution logical loop, remaining device(s) that do not support SDD are uncovered.
Thus, improved apparatuses and methods for facilitating collision resolution among multiple NFC-A devices may be desired.